ESPEC Criterion Series


Criterion Series

A wider range in a smaller footprint  
Adding to our popular Criterion benchtop series, ESPEC introduces the BTL-433 humidity chamber with the same quality features and expanded capabilities.  
The four cubic foot workspace is the largest to be found in a benchtop unit, while requiring less footprint than even smaller comparable chambers.   
The extended temperature and humidity ranges make testing at more extreme conditions possible. The vertical configuration saves bench space, plus the refrigeration’s ventilation design allows installation against a wall for even more space savings.  
ESPEC humidity system expertise  
Controlling humidity in a small environmental chamber can be especially challenging. ESPEC expertise in humidity control brings intelligent design that is carefully integrated into the BTL-433. The humidity subsystems are designed for reliability,  
convenience, and performance:  
  • An external steam generator allows expanded range and is easy to maintain.  
  • A separate de-humidification coil improves low humidity control and range.  
  • Wet-bulb humidity sensor is a “primary measurement method” for accuracy. It is also economical, easy to maintain, and reliable because it has no risk of failure due to over-saturation.  
  • Direct water supply connection is standard, with options for water filtering and recirculating water tank.  



This model was added by: WrenchHelp

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Depth 34 in
Height 46 in
Width 29 in
Power Requirements 115V, 16A max.
Additional Specifications Interior Volume 4 cu. ft.110 Liters
Interior Dimensions (W x D x H) 19.6" x 15" x 23.6" 500 x 380 x 600 mm
Temperature Range -20 to 180°C -4 to 354°F
Humidity Range (see chart for detail) 10% - 95% RH
Temperature Fluctuation (at control sensor) ±0.5
Humidity Fluctuation (at control sensor) ±3 “Price Rank”
  • Highest temperature: 180°C (354°F)
  • Humidity range: 10 to 95% RH
  • Chamber size: 4 cubic feet
  • Fully programmable with Watlow F4 controller

This model was added by: LabWrenchEditor

Edit Model

Depth 34 in
Height 46 in
Width 29 in
Power Requirements 208/230V 1ph 12A max
Additional Specifications Interior Volume: 4 cu. ft.
Interior Dimensions (W x D x H): 19.6" x 15" x 23.6"
Temperature Range: -70 to 180°C
Humidity Range: 10% - 95% RH
Temperature Fluctuation (at control sensor): ±0.5
Humidity Fluctuation (at control sensor): ±5


  • Stainless steel exterior and durable thermoformed plastic door  
  • Full thermal break around doorframe  
  • One 50mm (2") diameter cable port on left, with flexible silicone plug  
  • Three levels of overheat protection  
  • 115V main power with detachable eight-foot power cord  
  • High performance and quiet operation (65 dBa)  
  • Easy lift-off service panels  
  • Popular PID controller for test chambers  
  • Stores 40 different profiles (total 256 steps)  
  • Step types include: ramp, soak, jump, auto-start, and end  
  • RS-232C Modbus interface (free standard software)  


BTL Chamber

BTL Chamber

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ESPEC has been building test chambers in the United States since 1983. We are part of the ESPEC Group, which includes manufacturing facilities in Japan...

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Interior Corner Radius

What is the internal corner radius on Model BTL-433?

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